Many of today's communications devices, such as two-way radios and cellular telephones, connect to an array of accessories such as Public Speaker Microphones (PSMs) and Vehicular Adaptors (VAs). Some of these accessories, often referred to as “smart” accessories, contain an embedded non-volatile memory. When the accessory is operatively coupled to a communications device, the embedded non-volatile memory is used to provide data that identifies the accessory and its associated features (functions) that complements or replaces features of the communications device. When a “smart” accessory with an embedded non-volatile memory is operatively coupled to a communications device, the data contents of the non-volatile memory, such as accessory device type and function capability data (features), can be read by the device's processor. An example of an embedded non-volatile memory is a 1-Wire® bus Electrically Erasable Programmable Read Only Memory (EEPROM) available from Dallas Semiconductor. A 1-Wire® bus is a single wire power and data communications bus system that has a single bus master, typically a microcontroller, and one or more slaves.
Today, there is a trend towards allowing multiple accessories to be simultaneously operatively coupled to a communications device such as a two-way radio. For example, consider the two accessories one being a Public Speaker Microphone (PSM) and the other being a Vehicular Adapter (VA), when both of these accessories are operatively coupled to a compatible communications device, common features, that are common to the accessories, must be determined and the appropriate one of the accessories must be selected to provide one of the common features. To achieve the selection of an accessory to provide a common feature, differentiation of multiple accessories, and identification of their common features, can be provided by the data contents stored in their respective embedded non-volatile memories. However, a need exists for automatically selecting features of accessories operatively coupled to the communications device.
In this specification, including the claims, the terms ‘comprises’, ‘comprising’ or similar terms are intended to mean a non-exclusive inclusion, such that a method or apparatus that comprises a list of elements does not include those elements solely, but may well include other elements not listed.